"Il est" is just a more formal way to say "il y a". (Was this your problem?)

vijayjohn wrote:pl. les grand magasins (the point here is the spelling!)

It looks like a mistake.There are many compounds where "grand" doesn't agree in gender: une grand-mère. In such cases, the agreement in number (with feminine nouns only) is not clear: des grand(s)-mères.With masculine nouns, it always agrees: des grands-pères.And when it's not a 'real' compound, as far as I know, it always agrees: des grandes halles, des grands magasins.